Green’s Dictionary of Slang

top hat n.

[rhy. sl.]

1. a fool [= prat n.1 (5)].

[UK]R. Puxley Fresh Rabbit.
[UK]B. Kirkpatrick Wicked Cockney Rhy. Sl.

2. a cat.

[UK]P. Wright Cockney Dialect and Sl. 104: top ’at ‘cat.’.

3. a rat (the rodent).

[UK]R. Puxley Fresh Rabbit.
[UK]B. Kirkpatrick Wicked Cockney Rhy. Sl.

4. a chat.

[UK]B. Kirkpatrick Wicked Cockney Rhy. Sl.